This invention relates generally to selective call radio receivers, and more particularly, to a selective call radio paging receiver which combines multiple alerting devices which are operated alternatively rather than concurrently so as to improve battery performance.
Selective call radio receivers (commonly called "pagers") traditionally alert a user to an incoming message and may be categorized according to the types of alerts they generate. For example, tone only pagers simply emit a short audible alert tone to inform the user that he has received a message, but the pager does not actually convey the message to the user. After hearing the alert tone, the user typically calls a prearranged telephone number to receive the actual message. Tone and voice pagers include the necessary audio circuits and a small speaker to permit the user to hear a verbal message following the alert tone. Display pagers include a small alphanumeric character display by means of which a short message, such as a telephone number, may be displayed.
Recent market trends have resulted in the combining of several alerting devices in one pager which are then caused to operate concurrently. Such alerting devices include lamps, vibrators, automatic back-lighting for liquid crystal displays (LCD's), light emitting diodes (LED's), and alert tone generators with either escalating volume or traditional manual volume adjustment.
Obviously, each such alerting device consumes battery power. It follows that combining several alerting devices in one pager and operating the several devices concurrently can rapidly discharge the battery. In fact, it can be shown that the activation of two such alerting devices simultaneously will have a more deleterious impact on battery performance than if the multiple alerting devices were activated sequentially (i.e. only one alerting device on at a time) or in a complementary manner (i.e. one alerting device on while another is off and vice versa).